error: Base value must be equal to $FF00 for [$FF00+C]
    at ff00+c-bad.asm(8)
error: Expected constant expression: `xyz` is not constant at assembly time
    at ff00+c-bad.asm(9)
error: Base value must be equal to $FF00 for [$FF00+C]
    at ff00+c-bad.asm(9)
Assembly aborted with 3 errors!